1. Field of the Invention
The present general inventive concept relates to a print head and an inkjet printer including the same, and more particularly, to a print head improved in an ink drying quality and an inkjet printer including the same.
2. Description of the Related Art
In general, an ink jet printer jets a fine droplet of a printing ink onto a predetermined position to form an ink image on a printing medium.
As illustrated in FIG. 1, a conventional ink jet printer has a head unit 20 jetting an ink onto a printing medium S, and a controller (not shown) controlling an ink jet speed of the head unit 20.
The head unit 20 includes a base plate 21 and a plurality of print heads 23 supported by the base plate 21 and manufactured as a unit chip by a semiconductor process. The print heads 23 are disposed in a zigzag manner in the base plate 21 along a transverse direction Z to a feeding direction X of the printing medium S.
As illustrated in FIG. 2, each print head 23 has first through fourth nozzles N1 through N4 jetting a black K, cyan C, magenta M, and yellow Y inks, respectively. The plurality of first nozzles N1 through fourth nozzles N4 are linearly arranged in the transverse direction Z and form first through fourth nozzle groups L1 through L4, respectively.
FIG. 3 is an enlarged schematic view illustrating a pixel formed by an ink dot when a predetermined color image is formed on the printing medium S at a resolution of 1200 dpi. In FIG. 3, the ink dots Y, M, C and K are illustrated as if they are shifted by a short distance in the transverse direction Z to help understanding. However, the ink dots Y, M, C, and K are supposed to be formed in a pixel center point F.
As shown in FIG. 3, the yellow, magenta, cyan, and black inks are jetted during feeding the printing medium S in the feeding direction X, thereby forming ink dots Y, M, C, and K. Also, the controller (not shown) considers a transmitting speed of the printing medium S and controls the ink jet speed of the print head 23 so that the ink dots Y, M, C, and K can be formed on the same pixel centerline X1 in the feeding direction X.
However, the ink is jetted so that the ink dots Y, M, C, and K can be formed on the same pixel centerline X1 in the feeding direction X. Thus, the ink of different color is jetted before the previously jetted ink is dried, so that an ink drying performance is deteriorated and the color expression becomes unstable.
Also, an ink dot region for four colors has the same size with that for one color. Therefore, the ink dot region occupies a small area of a unit pixel on the printing medium S.
Meanwhile, to solve these problems, the controller needs to be redesigned to control an ink jet timing of each nozzle N1, N2, N3, and N4 of the print head 123 so that the ink dot regions can have centers E1, E2, E3, and E4.